The invention concerns an elastic clutch, specifically a two-mass flywheel for an internal combustion engine. A clutch of this category has been proposed in German Patent Application No. P3901467.3-12.
Clutches of this type are used in conjunction with internal combustion engines, specifically in vehicles, in order to improve the vibration behavior of the drive train in all operational and rotational speed ranges. To be suppressed are specifically torsional vibrations of the engine when passing through the critical speed of rotation.
In addition to springs for absorbing torsional jolts, the prior art clutch features for that purpose a damping device, which consists of one or more displacement chambers arranged on the circumference of the fluid-tight clutch that is filled with a damping medium. In displacement chamber is a cam which is effective in the peripheral direction. Another cam, which at a larger angle of rotation engages the displacement chamber, is located on the other clutch half. The enclosed damping medium is thereby displaced, through narrow gaps, into the interior of the clutch. To that end it was proposed to design the displacement chamber as an independent hermetic capsule in order to achieve a heavy damping especially when passing through the resonance speed of rotation. It has been demonstrated that the damping effect is not sufficient at specific operating conditions because the damping medium can still escape, at a large angle of rotation, through excessively wide gaps without contributing to damping.
Previously known from U.S. Pat. No. 2,520,180 is a clutch disk through which within the springs serving to transmit the torque each features a damping device. This device comprises a cylinder into which plunges a piston which is surrounded by an elastic boot. While fluid is to be drawn in through a predetermined opening and displaced again, this is supposed to take place without metallic friction. A damping effect graduated across the angle of rotation is not produced thereby.